There is proposed an apparatus which switches a connection destination site based on a white list which stores a reliable connection destination site.
The apparatus of concern receives a connection request from a client terminal. Then, the apparatus of concern connects to the connection destination site, if a connection destination site is stored in the white list. On the other hand, if a connection destination site which the received connection request indicates is not stored in the white list, the apparatus of concern, on receiving for example, a connection request from the client terminal to connect to a substitutive site, connects to the substitutive site.
Patent Literature 1: Japanese Laid-open Patent Publication No. 2010-182081.
There is another apparatus which switches a communication route of a communication packet received from a client terminal, based on a white list which stores identification information for identifying a reliable communication opposite party. On receiving a communication start request from the client terminal, if information for identifying a communication opposite party of the client terminal is stored in the white list, the apparatus of concern stores information (for example, an IP address) for identifying an apparatus corresponding to the communication opposite party of concern, into a routing table. On the other hand, if information for identifying a communication opposite party of the client terminal is not stored in the white list, the apparatus of concern does not store information for identifying an apparatus corresponding to the communication opposite party into the routing table.
Thereafter, the apparatus of concern, on receiving a communication packet from the client terminal, collates a destination IP address included in the communication packet with the routing table, to confirm whether the destination IP address is stored in the routing table (hereafter appropriately described as collation processing and confirmation processing).
Then, when the destination IP address is stored in the routing table, the apparatus of concern transfers the communication packet received from the client terminal to a first communication route. Here, the first communication route is, for example, a communication route which does not include a VPN (Virtual Private Network).
On the other hand, when the destination IP address is not stored in the routing table, the apparatus of concern transfers the communication packet received from the client terminal to a second communication route. Here, the second communication route is, for example, a communication route which includes a VPN. Incidentally, the above communication packet is transferred to an apparatus corresponding to the communication opposite party through the communication route.
Now, there is assumed a case such that the client terminal simultaneously communicates with a multiplicity of communication opposite parties stored in the white list. In this case, each IP address of apparatuses corresponding to the multiplicity of communication opposite parties is stored in the routing table. The apparatus of concern, when simultaneously communicating with the multiplicity of communication opposite parties, may simultaneously execute the above-mentioned collation processing and the confirmation processing for each communication packet, causing increased processing loads for the collation processing and the confirmation processing.
As a result, transfer processing for the communication packet in the apparatus of concern delays, causing an arrival delay of the communication packet from the client terminal to each communication opposite party. As a result, there is deterioration in the quality of a communication service which the apparatus of concern provides to the client.